The present disclosure relates generally to a wearable apparatus mounted in an orientation on a head of a human operator and operative for electro-optically reading targets, such as bar code symbols, and, more particularly, to an arrangement for, and a method of, calibrating the apparatus to consistently face and read the targets, no matter the orientation of the apparatus on the head.
Moving laser beam readers and solid-state imaging readers, in both handheld and/or hands-free modes of operation, have both been used to electro-optically read targets, such as one- and two-dimensional bar code symbol targets, and/or non-symbol targets, such as documents. In certain venues, for example, in a warehouse, a hands-free reader for taking a product inventory is beneficial, because an operator has his/her hands readily available to manipulate objects, and/or to operate handheld, mobile devices, such as smartphones, tablets, computers, radios, radio frequency (RF) identification (RFID) readers, and like portable devices. One type of hands-free reader is mounted on a head of the operator. The head-mounted reader can be mounted on, and incorporated in, a headset, a headband, a helmet, a hat, a cap, a pair of eyeglasses, and like headgear and eyepieces.
Although generally satisfactory for its intended purpose, the head-mounted reader could be mounted in many different orientations on the head. The operator could remove the reader from, and put the reader back on, his/her head multiple times in different, non-repeatable, locations thereon based on multiple factors, for example, on comfort and convenience. When the reader is worn by different operators whose heads are of different sizes and shapes, the orientations are still more varied. In order to successfully read a target, the operator typically directly views the target with his/her eyes along a sightline, and the head-mounted reader must face, and be aimed at, the same target. However, this might not occur if the head-mounted reader is pointing in one direction in one orientation, and in other directions in other orientations, especially if such orientations are not predictable. The operator is often forced to “hunt” for each target by constantly moving his/her head up-and-down, and/or by twisting his/her head from side-to-side. This not only slows down the reading and degrades reading performance, but also could eventually lead to operator fatigue and possible injury, especially to the operator's neck.
Accordingly, there is a need to consistently and reliably aim the head-mounted reader at the target to be read, no matter the orientation of the head-mounted reader on the head of the operator, to resist operator fatigue and injury, and to enhance reading performance.
Skilled artisans will appreciate that elements in the figures are illustrated for simplicity and clarity and have not necessarily been drawn to scale. For example, the dimensions and locations of some of the elements in the figures may be exaggerated relative to other elements to help to improve understanding of embodiments of the present invention.
The arrangement and method components have been represented where appropriate by conventional symbols in the drawings, showing only those specific details that are pertinent to understanding the embodiments of the present invention so as not to obscure the disclosure with details that will be readily apparent to those of ordinary skill in the art having the benefit of the description herein.